diff --git a/src/ast_to_c.ml b/src/ast_to_c.ml
index 0789b76..f98ffa3 100644
--- a/src/ast_to_c.ml
+++ b/src/ast_to_c.ml
@@ -1,6 +1,6 @@
 open Ast
-open Cast
-open C_utils
+open Intermediate_ast
+open Intermediate_utils
 open Cprint
 open Utils
 
@@ -56,7 +56,6 @@ let ast_to_cast (nodes: t_nodelist) (h: node_states): c_nodelist =
     end
     nodes
 
-
 (** The following function defines the [node_states] for the nodes of a program,
   * and puts them in a hash table. *)
 let make_state_types nodes: node_states =
@@ -198,21 +197,26 @@ let make_state_types nodes: node_states =
 (** The following function prints the code to remember previous values of
   * variables used with the pre construct. *)
 let cp_prevars fmt (node, h) =
-  Format.fprintf fmt
-    "\n\t/* Remember the values of variables used in the [pre] construct */\n";
   let node_st = Hashtbl.find h node.cn_name in
-  List.iter
-    (fun v -> (** Note that «dst_array = src_array» should hold. *)
-      let (src_array, src_idx) = Hashtbl.find node_st.nt_map (v, false) in
-      let (dst_array, dst_idx) = Hashtbl.find node_st.nt_map (v, true) in
-      Format.fprintf fmt "\t%s[%d] = %s[%d];\n"
-        dst_array dst_idx src_array src_idx)
-    node_st.nt_prevars
+  match (Hashtbl.find h node.cn_name).nt_prevars with
+  | [] -> ()
+  | l ->
+      Format.fprintf fmt
+        "\n\t/* Remember the values used in the [pre] construct */\n";
+      List.iter
+        (fun v -> (** Note that «dst_array = src_array» should hold. *)
+          let (src_array, src_idx) = Hashtbl.find node_st.nt_map (v, false) in
+          let (dst_array, dst_idx) = Hashtbl.find node_st.nt_map (v, true) in
+          Format.fprintf fmt "\t%s[%d] = %s[%d];\n"
+            dst_array dst_idx src_array src_idx)
+        l
+
+
 
 (** The following function defines the behaviour to have at the first
   * execution of a node, namely:
   *   - initialize the states of auxiliary nodes
-  * *)
+  *)
 let cp_init_aux_nodes fmt (node, h) =
   let rec aux fmt (node, nst, i) =
     match find_app_opt node.cn_equations i with
@@ -220,7 +224,7 @@ let cp_init_aux_nodes fmt (node, h) =
     | Some n ->
       begin
       Format.fprintf fmt "%a\t\tstate->aux_states[%d] = malloc (sizeof (%s));\n\
-          \t\t(%s*)(state->aux_states[%d])->is_init = true;\n"
+          \t\t((%s*)(state->aux_states[%d]))->is_init = true;\n"
         aux (node, nst, i-1)
         (i-1) (Format.asprintf "t_state_%s" n.n_name)
         (Format.asprintf "t_state_%s" n.n_name) (i-1)
@@ -235,12 +239,33 @@ let cp_init_aux_nodes fmt (node, h) =
         aux (node, nst, nst.nt_count_app)
     end
 
-let rec cp_node fmt (node, h) =
-  Format.fprintf fmt "%a\n{\n%a\t\tTODO...\n\n\tstate->is_init = false;\n%a}\n"
+
+
+(** The following function prints one equation of the program into a set of
+  * instruction ending in assignments. *)
+let cp_equation fmt (eq, hloc) =
+  Format.fprintf fmt "\t\t/* TODO! */\n"
+
+
+
+(** [cp_equations] prints the node equations. *)
+let rec cp_equations fmt (eqs, hloc) =
+  match eqs with
+  | [] -> ()
+  | eq :: eqs ->
+    Format.fprintf fmt "%a%a"
+      cp_equation (eq, hloc)
+      cp_equations (eqs, hloc)
+
+(** [cp_node] prints a single node *)
+let cp_node fmt (node, h) =
+  Format.fprintf fmt "%a\n{\n%a%a\n\n\tstate->is_init = false;\n%a}\n"
     cp_prototype (node, h)
     cp_init_aux_nodes (node, h)
+    cp_equations (node.cn_equations, Hashtbl.find h node.cn_name)
     cp_prevars (node, h)
 
+(** [cp_nodes] recursively prints all the nodes of a program. *)
 let rec cp_nodes fmt (nodes, h) =
   match nodes with
   | [] -> ()
@@ -251,6 +276,7 @@ let rec cp_nodes fmt (nodes, h) =
 
 
 
+(** main function that prints a C-code from a term of type [t_nodelist]. *)
 let ast_to_c prog =
   let prog_st_types = make_state_types prog in
   let prog: c_nodelist = ast_to_cast prog prog_st_types in
diff --git a/src/cprint.ml b/src/cprint.ml
index a64e8fa..5f191ae 100644
--- a/src/cprint.ml
+++ b/src/cprint.ml
@@ -1,5 +1,5 @@
-open C_utils
-open Cast
+open Intermediate_utils
+open Intermediate_ast
 open Ast
 
 (** This file contains extrimely simple functions printing C code. *)
diff --git a/src/cast.ml b/src/intermediate_ast.ml
similarity index 100%
rename from src/cast.ml
rename to src/intermediate_ast.ml
diff --git a/src/c_utils.ml b/src/intermediate_utils.ml
similarity index 98%
rename from src/c_utils.ml
rename to src/intermediate_utils.ml
index 717b4a5..c964e50 100644
--- a/src/c_utils.ml
+++ b/src/intermediate_utils.ml
@@ -1,4 +1,4 @@
-open Cast
+open Intermediate_ast
 
 let rec find_app_opt eqs i =
   let rec find_app_expr_opt i = function
diff --git a/src/pp.ml b/src/lustre_pp.ml
similarity index 100%
rename from src/pp.ml
rename to src/lustre_pp.ml
diff --git a/src/main.ml b/src/main.ml
index 7acfc16..80c3678 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -17,7 +17,7 @@ let exec_passes ast main_fn verbose debug passes f =
         match p verbose debug main_fn ast with
         | None -> (exit_error ("Error while in the pass "^n^".\n"); exit 0)
         | Some ast -> (
-        debug (Format.asprintf "Current AST (after %s):\n%a\n" n Pp.pp_ast ast);
+        debug (Format.asprintf "Current AST (after %s):\n%a\n" n Lustre_pp.pp_ast ast);
         aux ast passes)
   in
   aux ast passes
@@ -34,7 +34,6 @@ let _ =
   let debug = ref false in
   let ppast = ref false in
   let nopopt = ref false in
-  let simopt = ref false in
   let passes = ref [] in
   let source_file = ref "" in
   let testopt = ref false in
@@ -51,7 +50,6 @@ let _ =
       ("-debug", Arg.Set debug, "Output a lot of debug information");
       ("-p", Arg.String (fun s -> passes := s :: !passes),
             "Add a pass to the compilation process");
-      ("-sim", Arg.Set simopt, "Simulate the main node");
       ("-o", Arg.Set_string output_file, "Output file (defaults to [out.c])");
     ] in
   Arg.parse speclist anon_fun usage_msg ;
@@ -93,7 +91,7 @@ let _ =
       begin
         close_in_noerr inchan;
         Format.printf "Syntax error at %a: %s\n\n"
-          Pp.pp_loc (l, !source_file) s;
+          Lustre_pp.pp_loc (l, !source_file) s;
         exit 0
       end
     | Parsing.Parse_error ->
@@ -101,7 +99,7 @@ let _ =
         close_in_noerr inchan;
         Parsing.(
         Format.printf "Syntax error at %a\n\n"
-          Pp.pp_loc ((symbol_start_pos (), symbol_end_pos()), !source_file));
+          Lustre_pp.pp_loc ((symbol_start_pos (), symbol_end_pos()), !source_file));
         exit 0
       end
     in
@@ -121,19 +119,14 @@ let _ =
     in
 
   print_debug (Format.asprintf "Initial AST (before executing any passes):\n%a"
-                Pp.pp_ast ast) ;
+                Lustre_pp.pp_ast ast) ;
   exec_passes ast main_fn print_verbose print_debug passes
-    begin
-    if !simopt
-      then Simulation.simulate main_fn
-      else
-        begin
-        if !ppast
-          then (Format.printf "%a" Pp.pp_ast)
-          else (
-            if !nopopt
-              then (fun _ -> ())
-              else Ast_to_c.ast_to_c)
-        end
-    end
+  begin
+  if !ppast
+    then (Format.printf "%a" Lustre_pp.pp_ast)
+    else (
+      if !nopopt
+        then (fun _ -> ())
+        else Ast_to_c.ast_to_c)
+  end
 
diff --git a/src/simulation.ml b/src/simulation.ml
deleted file mode 100644
index e7ba3db..0000000
--- a/src/simulation.ml
+++ /dev/null
@@ -1,92 +0,0 @@
-open Ast
-
-type sim_var =
-  | SIVar of ident * (int option)
-  | SBVar of ident * (bool option)
-  | SRVar of ident * (real option)
-
-type sim_node_st =
-  {
-    node_outputs: sim_var list;
-    node_loc_vars: sim_var list;
-    node_inner_nodes: sim_node list;
-  }
-and sim_node_step_fn =
-  sim_node_st -> sim_var list -> (sim_var list * sim_node_st)
-and sim_node = sim_node_st * sim_node_step_fn
-
-let pp_sim fmt ((sn, _): sim_node) =
-  let rec aux fmt vars =
-    match vars with
-    | [] -> ()
-    | SIVar (s, None) :: t ->
-        Format.fprintf fmt "\t<%s : int> uninitialized yet.\n%a" s aux t
-    | SBVar (s, None) :: t ->
-        Format.fprintf fmt "\t<%s : bool> uninitialized yet.\n%a" s aux t
-    | SRVar (s, None) :: t ->
-        Format.fprintf fmt "\t<%s : real> uninitialized yet.\n%a" s aux t
-    | SIVar (s, Some i) :: t ->
-        Format.fprintf fmt "\t<%s : int> = %d\n%a" s i aux t
-    | SBVar (s, Some b) :: t ->
-        Format.fprintf fmt "\t<%s : bool> = %s\n%a" s (Bool.to_string b) aux t
-    | SRVar (s, Some r) :: t ->
-        Format.fprintf fmt "\t<%s : real> = %f\n%a" s r aux t
-  in
-  if sn.node_loc_vars <> []
-    then
-      Format.fprintf fmt "State of the simulated node:\n\
-                          \tOutput variables:\n%a
-                          \tLocal variables:\n%a"
-        aux sn.node_outputs
-        aux sn.node_loc_vars
-    else
-      Format.fprintf fmt "State of the simulated node:\n\
-                          \tOutput variables:\n%a
-                          \tThere are no local variables:\n"
-        aux sn.node_outputs
-
-
-exception MySimulationException of string
-
-let fetch_node (p: t_nodelist) (s: ident) : t_node =
-  match List.filter (fun n -> n.n_name = s) p with
-  | [e] -> e
-  | _ -> raise (MySimulationException (Format.asprintf "Node %s undefined." s))
-
-let fetch_var (l: sim_var list) (s: ident) =
-  match List.filter
-    (function
-      | SBVar (v, _) | SRVar (v, _) | SIVar (v, _) -> v = s) l with
-  | [v] -> v
-  | _ -> raise (MySimulationException
-                (Format.asprintf "Variable %s undefined." s))
-
-(** TODO! *)
-let make_sim (main_fn: ident) (p: t_nodelist): sim_node =
-  let main_n = fetch_node p main_fn in
-  let node_outputs =
-    List.map
-      (function
-        | IVar s -> SIVar (s, None)
-        | BVar s -> SBVar (s, None)
-        | RVar s -> SRVar (s, None))
-      (snd main_n.n_outputs) in
-  let node_loc_vars: sim_var list =
-    List.map
-      (function
-        | IVar s -> SIVar (s, None)
-        | BVar s -> SBVar (s, None)
-        | RVar s -> SRVar (s, None))
-      (snd main_n.n_local_vars) in
-  let node_inner_nodes = (* TODO! *) [] in
-  ({node_outputs = node_outputs;
-    node_loc_vars = node_loc_vars;
-    node_inner_nodes = node_inner_nodes; },
-    (fun s l -> (s.node_outputs, s)))
-
-
-
-let simulate main_fn ast =
-  let sim_ast = make_sim main_fn ast in
-  Format.printf "Initial state:\n%a" pp_sim sim_ast
-
diff --git a/src/test.node b/tests/test.node
similarity index 100%
rename from src/test.node
rename to tests/test.node
diff --git a/src/test2.node b/tests/test2.node
similarity index 100%
rename from src/test2.node
rename to tests/test2.node
diff --git a/src/test_pre.node b/tests/test_pre.node
similarity index 100%
rename from src/test_pre.node
rename to tests/test_pre.node